This application is directed to improvements in material grinders.
Generally speaking, coffee grinders for home must be relatively simple and reliable, and yet durable and reasonably maintenance free. These goals must be accomplished within strict budgetary considerations, making it possible to design, assemble and market a coffee grinder at a price suitable for the consumer products market.
Coffee popularity has been increasing during recent years and, as a result of this popularity, many consumers now demand fresh ground coffee for their home coffee brewing machines. For the distinguishing palate, the whole bean coffee provides a more flavorful brewed coffee than commercially available pre-ground coffee. Additionally, coffee drinkers who prefer to mix their own blend of coffee beans find it necessary to have a coffee grinder at home. As an additional factor, whole bean coffee retains its flavor and freshness much longer than pre-ground coffee and as such is the choice of discriminating coffee drinkers.
The grinding of coffee requires a grinding apparatus which has sufficient power to fully grind the coffee to a desired size, but yet does not bruise, burn, or abrade the coffee beans during the grinding operation. Under ideal conditions, coffee beans should pass through the grinder path only once to avoid excessive grinding into undesirably small particles as well as burning or abrading against the other particles or against the grinding components. More specifically, when coffee beans are ground they should pass through the grinder relatively quickly and be ground to a desired uniform finished particulate size. Unfortunately, many currently available coffee grinding machines do not satisfy these ideal conditions.
It has been found that many consumer devices encounter a degree of difficulty in grinding beans which have an oily or sticky coating. While some types of coffee beans tend toward a dry outer surface, a number of darker roasts have an oily or sticky coating. The oily or sticky coating can result from the roasting process in which oils evolve from the inside of the coffee beans to the surface as commonly found in expresso roast, French roast and most commonly in Italian roast coffee. Additionally, beans also may be sticky or oily as a result of a flavoring process or as preservative measure using a light non-flavored oil to lock in the aroma and flavor of a particular coffee bean after roasting.
When the "sticky beans" are placed in a coffee grinder, they have a tendency to stick to surfaces in the hopper and grinder thereby preventing complete grinding of the coffee disposed in the coffee hopper. For example, sticky beans cause a problem when they become stuck in the hopper and require manual vibration or moving in order to cause the beans to flow into the grinding portion of the apparatus. Additionally, sticky beans may stick to the surfaces inside the grinding portion and can block the flow into the grinding portion.